Methods of processing a glass ribbon

ABSTRACT

Methods of processing a glass ribbon are provided. The method includes the step of traversing the glass ribbon through a travel path at a predetermined velocity and severing the glass ribbon to create an upstream web and a downstream web. The method further includes the step of increasing a relative velocity of a downstream edge portion with respect to an upstream edge portion to create a gap between an upstream severed edge and a downstream severed edge. In other example methods, a segment of the glass ribbon is removed to create a gap between an upstream severed edge and a downstream severed edge. In still further example methods, an upstream severed edge is directed along a second travel path to create a gap between the upstream severed edge and a downstream severed edge.

This application is a divisional of U.S. patent application Ser. No.13/673,385, filed on Nov. 9, 2012, the content of which is relied uponand incorporated herein by reference in its entirety, and the benefit ofpriority under 35 U.S.C. §120 is hereby claimed.

TECHNICAL FIELD

The present invention relates generally to methods of processing a glassribbon and, more particularly, to methods of processing a glass ribbonthat creates a gap between an upstream severed edge and a downstreamsevered edge.

BACKGROUND

Glass ribbon is known to be used to manufacture various glass productssuch as LCD sheet glass. Processing of the glass ribbon can be performedwith a “roll-to-roll” process where glass ribbon is unwound from anupstream storage roll and then subsequently wound on a downstreamstorage roll.

SUMMARY

The following presents a simplified summary of the disclosure in orderto provide a basic understanding of some example aspects described inthe detailed description.

In a first aspect, a method of processing a glass ribbon includes thestep (I) of traversing the glass ribbon through a travel path at apredetermined velocity. The method further includes the step (II) ofsevering the glass ribbon along a direction transverse to the travelpath to create an upstream web comprising a upstream edge portionincluding a upstream severed edge and a downstream web comprising andownstream edge portion including an downstream severed edge. The methodfurther includes the step (III) of increasing a relative velocity of thedownstream edge portion with respect to the upstream edge portion tocreate a gap between the upstream severed edge and the downstreamsevered edge.

In one example of the first aspect, step (III) includes increasing thevelocity of the downstream edge portion to provide the increasedrelative velocity of the downstream edge portion with respect to theupstream edge portion.

In another example of the first aspect, an amount of the downstream webis collected by an accumulator to increase the velocity of thedownstream edge portion.

In still another example of the first aspect, step (III) comprisesdecreasing the velocity of the upstream edge portion to provide theincreased relative velocity of the downstream edge portion with respectto the upstream edge portion.

In yet another example of the first aspect, an amount of the upstreamweb is collected by an accumulator to decrease the velocity of theupstream edge portion.

In still another example of the first aspect, the glass ribbon of step(I) includes a width extending transverse to the travel path between afirst side edge and a second side edge. At least one of the first orsecond side edge includes a handling tab with a mounting portionincluding an aperture configured to expose the entire respective firstor second side edge within a target area. Step (II) includes severingthe glass ribbon through the at least one of the first or second sideedge within the target area.

In another example of the first aspect, step (II) is initiated inresponse to a storage roll reaching a predetermined storage capacity.

In yet another example of the first aspect, after step (III), thedownstream web is wound on a first storage roll, and the upstream edgeportion of the upstream web is introduced to a second storage roll tobegin winding the upstream web on the second storage roll.

The first aspect may be carried out alone or in combination with one ormore of the examples of the first aspect discussed above.

In a second aspect, a method of processing a glass ribbon comprising thestep (I) of traversing the glass ribbon through a travel path at apredetermined velocity. The method further includes the step (II) ofsevering the glass ribbon at a first location transverse to the travelpath. The method still further includes the step (III) of severing theglass ribbon at a second location transverse to the travel path suchthat a segment of glass ribbon is severed from an upstream web includingan upstream severed edge and a downstream web including a downstreamsevered edge. The method also includes the step (IV) of removing thesegment of the glass ribbon such that a gap is created between theupstream severed edge and the downstream severed edge.

In one example of the second aspect, a sever path created during step(II) is substantially parallel to a sever path created during step(III).

In another example of the second aspect, the glass ribbon of step (I)includes a width extending transverse to the travel path between a firstside edge and a second side edge, wherein at least one of the first orsecond side edge includes a handling tab with a mounting portionincluding an aperture configured to expose the entire respective firstor second side edge within a target area. Furthermore, step (II)includes severing the glass ribbon through the at least one of the firstor second side edge within the target area.

In still another example of the second aspect, step (II) is initiated inresponse to a storage roll reaching a predetermined storage capacity.

In yet another example of the second aspect, after step (IV), thedownstream web is wound on a first storage roll, and the downstreamsevered edge of the upstream web is introduced to a second storage rollto begin winding the upstream web on the second storage roll.

The second aspect may be carried out alone or in combination with one ormore of the examples of the second aspect discussed above.

In a third aspect, a method of processing a glass ribbon comprises thestep (I) of traversing the glass ribbon through a first travel path at apredetermined velocity to be wound on a first storage roll. The methodfurther includes the step (II) of severing the glass ribbon along adirection transverse to the travel path to create an upstream webincluding an upstream severed edge and a downstream web including adownstream severed edge. The method further includes the step (III) ofdirecting the upstream severed edge along a second travel path to createa gap between the upstream severed edge and the downstream severed edge.

In accordance with one example of the third aspect, step (III) includesdirecting the upstream severed edge along the second travel path to bewound on a second storage roll.

In accordance with another example of the third aspect, the glass ribbonof step (I) includes a width extending transverse to the travel pathbetween a first side edge and a second side edge, wherein at least oneof the first or second side edge includes a handling tab with a mountingportion including an aperture configured to expose the entire respectivefirst or second side edge within a target area. Furthermore, step (II)includes severing the glass ribbon through the at least one of the firstor second side edge within the target area.

In accordance with yet another example of the third aspect, step (II) isinitiated in response to the first storage roll reaching a predeterminedstorage capacity.

The third aspect may be carried out alone or in combination with one ormore of the examples of the third aspect discussed above.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects are better understood when the followingdetailed description is read with reference to the accompanyingdrawings, in which:

FIG. 1 is a schematic illustration of an edge separation apparatus;

FIG. 2 is a schematic illustration of an apparatus for severing a glassribbon;

FIG. 3 is a sectional view of the edge separation apparatus along line3-3 of FIG. 1;

FIG. 4 is a sectional view along line 4-4 of FIG. 2 showing a scribe tipbeginning to form a predetermined flaw in the first side of the glassribbon;

FIG. 5 is a sectional view similar to FIG. 4 after forming thepredetermined flaw;

FIG. 6 is an enlarged view of a severing zone of FIG. 2 with a portionof the glass ribbon including a predetermined flaw in a firstorientation;

FIG. 7 is a view similar to FIG. 6 with a force being applied to thesecond side of the glass ribbon to bend a target segment of the glassribbon;

FIG. 8 is another view similar to FIG. 7 with the predetermined flawapproaching a severing position;

FIG. 9 illustrates the step of severing the central portion of the glassribbon between opposed edge portions at the predetermined flaw locatedin the severing zone;

FIG. 10 illustrates the portion of the glass ribbon being returned tothe first orientation;

FIG. 11 a schematic illustration demonstrating the step of switchingbetween a first storage roll and a second storage roll;

FIG. 12 is a schematic view of another example apparatus for severing aglass ribbon;

FIG. 13 is a sectional view along line 13-13 of FIG. 12;

FIG. 14 is an enlarged view of the apparatus for severing a glass ribbonfrom FIG. 12 with the target segment in a first orientation;

FIG. 15 is similar to FIG. 14 with the target segment in a bentorientation;

FIG. 16 is similar to FIG. 15 with the target segment in the bentorientation and the glass ribbon being severed at the predetermined flawlocated in the severing zone;

FIG. 17 is a view similar to FIG. 6 also showing pinch rolls andvelocity indicators for each set of pinch rolls;

FIG. 18 is similar to FIG. 17 demonstrating the step of increasing thevelocity of the downstream edge portion;

FIG. 19 is similar to FIG. 17 demonstrating the step of decreasing thevelocity of the upstream edge portion;

FIG. 20 is a view similar to FIG. 6 also showing glass ribbonaccumulators for the upstream web and the downstream web;

FIG. 21 is similar to FIG. 20 demonstrating the step of collecting anamount of the downstream web in the downstream accumulator;

FIG. 22 is similar to FIG. 20 demonstrating the step of collecting anamount of the upstream web in the upstream accumulator;

FIG. 23 is a view similar to FIG. 6 demonstrating the step of removing asegment of the glass ribbon;

FIG. 24 is a view similar to FIG. 6 demonstrating the step of directingthe upstream severed edge along a second travel path; and

FIG. 25 is a sectional view along line 25-25 of FIG. 11.

DETAILED DESCRIPTION

Examples will now be described more fully hereinafter with reference tothe accompanying drawings in which example embodiments are shown.Whenever possible, the same reference numerals are used throughout thedrawings to refer to the same or like parts. However, aspects may beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein.

FIGS. 1 and 2 illustrate just one example of an apparatus 101 forfabricating a glass ribbon 103. As shown, FIG. 2 is a continuation ofFIG. 1, wherein FIGS. 1 and 2 can be read together as the overallconfiguration of the apparatus 101. Examples of the apparatus 101 caninclude an edge separation apparatus 101 a illustrated in FIG. 1although the edge separation apparatus may be omitted in furtherexamples. In addition or alternatively, as shown in FIG. 2, theapparatus 101 can also include an apparatus 101 b for severing a glassribbon. The edge separation apparatus 101 a, for example, may beoptionally employed to remove beads or other edge imperfections asdescribed more fully below. Alternatively, the edge separation apparatus101 a may be used to divide the glass ribbon for further processing ofthe central portion and/or edge portions. The apparatus 101 b forsevering a glass ribbon can be provided, for example, to help sever asheet to the desired length, remove an undesirable segment of glassribbon from the source of glass ribbon, and/or facilitate switchingbetween a first storage roll and a second storage roll with minimal, ifany, disruption in traversing of the glass ribbon from the source ofglass ribbon.

The glass ribbon 103 for the apparatus 101 can be provided by a widerange of glass ribbon sources. FIG. 1 illustrates two example sources105 of glass ribbon 103 although other sources may be provided infurther examples. For instance, as shown in FIG. 1, the source 105 ofglass ribbon 103 can comprise a down draw glass forming apparatus 107.As schematically shown, the down draw glass forming apparatus 107 caninclude a forming wedge 109 at the bottom of a trough 111. In operation,molten glass 113 can overflow the trough 111 and flow down oppositeconverging sides 115, 117 of the forming wedge 109. Converging sides115, 117 meet at a root 119. The two sheets of molten glass aresubsequently fused together as they are drawn off the root 119 of theforming wedge 109. As such, the glass ribbon 103 may be fusion downdrawn to traverse in a downward direction 121 off the root 119 of theforming wedge 109 and directly into a downward zone 123 positioneddownstream from the down draw glass forming apparatus 107. Other downdraw forming methods for the glass ribbon source 105 such as slot draware also possible. Regardless of the source or method of production, theglass ribbon 103 can possibly have a thickness of ≦500 microns, ≦300microns, ≦200 microns, or ≦100 microns. In one example, the glass ribbon103 can include a thickness of from about 50 microns to about 300microns, for example 50, 60, 80, 100, 125, 150, 175, 200, 225, 250, 260,270, 280, 290, or 300 microns, although other thicknesses may beprovided in further examples. The glass ribbon 103 can possibly have awidth of ≧20 mm, ≧50 mm, ≧100 mm, ≧500 mm, or ≧1000 mm. The glass ribbon103 can possibly have a variety of compositions including but notlimited to soda-lime, borosilicate, alumino-borosilicate,alkali-containing, or alkali-free. The glass ribbon 103 can possiblyhave a coefficient of thermal expansion of ≦15 ppm/° C., ≦10 ppm/° C.,or ≦5 ppm/° C. The glass ribbon 103 can possibly have a speed as ittraverses along travel direction 112 of ≧50 mm/s, ≧100 mm/s, or ≧500mm/s.

As shown by the cross section of FIG. 3, the glass ribbon 103 caninclude a pair of opposed edge portions 201, 203 and a central portion205 spanning between the opposed edge portions 201, 203. Due to the downdraw fusion process, the edge portions 201, 203 of the glass ribbon mayhave corresponding beads 207, 209 with a thickness “T₁” that is greaterthan a thickness “T₂” of the central portion 205 of the glass ribbon103. The apparatus 101 can be designed to process glass ribbons 103 witha thin central portion 205, such as glass ribbons with a thickness “T₂”in a range of from about 20 microns to about 300 microns (e.g., 20, 30,40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 170, 190, 210,230, 250, 260, 270, 280, 290, or 300 microns, for example), such as fromabout 50 microns to about 300 microns, such as from about 85 microns toabout 150 microns although glass ribbons with other thicknesses may beprocessed in further examples. In addition or alternatively to what isshown in FIG. 3, the edge beads 207, 209 may have non-circular shapessuch as elliptical, oblong, rectangular, or other shapes with convex orother features.

Turning back to FIG. 1, another example source 105 of glass ribbon 103can comprise a coiled spool 124 of glass ribbon 103. For example, glassribbon 103 may be wound into the coiled spool 124 after being drawn intoa glass ribbon, for example, with the down draw glass forming apparatus107. The glass ribbon 103 rolled or coiled on the spool 124 may or maynot have the illustrated edge beads 201, 203. However, if the greaterthickness of the edge portions 201, 203 are present, they may increasethe minimum bend radius required to avoid cracking or breaking the glassribbon. As such, if coiled, the glass ribbon 103 may be coiled with arelatively large bend radius such that a given length of glass ribbon103 would require a coiled spool 124 with a relatively large diameter“D₁”. Thus, if the source 105 comprises the coiled spool 124, the glassribbon 103 may be uncoiled from the coiled spool 124 of glass ribbon 103to traverse the glass ribbon 103 in the downward direction 121 into thedownward zone 123.

FIGS. 1 and 2 illustrate aspects of just one example edge separationapparatus 101 a that may be optionally included although, if provided,other edge separation apparatus may be incorporated in further examples.As shown in FIG. 1, the optional edge separation apparatus can include abending zone 125 downstream from the downward zone 123. In the bendingzone 125, the edge separation apparatus 101 a can be designed to permitthe glass ribbon 103 to travel through a curved path such that an uppersurface 127 of the glass ribbon 103 comprises an upwardly concavesurface as the ribbon bends through a radius “R” within the bending zone125. The radius “R” may be greater than a minimum bend radius of theglass ribbon 103 to avoid excessive stress concentrations in the glassribbon 103. The glass ribbon 103 may extend through various arcs withinthe bending zone 125 such that a pre-bending portion 131 of the glassribbon 103 entering the bending zone 125 can extend at various angleswith respect to a post-bending portion 133 of the glass ribbon 103. Forexample, as shown in FIG. 1, the angle “A” between the pre-bendingportion 131 and the post-bending portion 133 can comprise an acute anglealthough angles of 90° or more may be provided in further examples whilestill providing the upwardly concave surface 127.

The edge separation apparatus 101 a can further include an optionalbending support member 135 in examples where the elevation of a lowerportion 137 of the glass ribbon within the bending zone 125 is lowerthan a lateral travel elevation of the glass ribbon passing throughsupport portions leading to a cutting zone 147. The bending supportmember 135, if provided, can comprise a non-contact support member 135designed to support the glass ribbon 103 without touching the opposedfirst and second sides 141, 139 of the central portion 205 of the glassribbon 103. For example, the bending support member 135 can comprise oneor more curved air bars configured to provide a cushion of air to spacethe glass ribbon from contacting the bending support member 135.

Examples of the edge separation apparatus 101 a can include lateralguides 143, 145 to help orient the glass ribbon 103 in the correctlateral position relative to a travel direction 112 of the glass ribbon103. For example, as schematically shown in FIG. 3, the lateral guidescan each comprise rollers 211 configured to engage a corresponding oneof the opposed edge portions 201, 203, or if provided, correspondinghandling tabs 651, 653. Handling tabs 651, 653 may be, for example, apolymeric tape applied to the edge portions. Corresponding forces 213,215 applied to the edge portions 201, 203 by the corresponding lateralguides 143, 145 can help properly shift and align the glass ribbon 103in the proper lateral orientation along a direction of an axis 217transverse to the travel direction 112 of the glass ribbon 103. Thecutting zone produces an edge quality that possibly enables the centralportion 205 to be bent at a radius of ≦500 mm, ≦300 mm, ≦200 mm, ≦100mm, or ≦50 mm.

As further illustrated, the lateral guides 143, 145 can be designed toengage the edge portions 201, 203, or corresponding handling tabs 651,653, without engaging the central portion 205 of the glass ribbon 103.As such, the pristine surfaces of the opposed sides 139, 141 of thecentral portion 205 of the glass ribbon 103 can be maintained whileavoiding undesired scratching or other surface contamination that mightotherwise occur if the lateral guides 143, 145 were to engage either ofthe opposed first and second sides 141, 139 of the central portion 205of the glass ribbon 103. Engagement on the edge portions 201, 203, orcorresponding handling tabs 651, 653, also prevents damage orcontamination to opposed edges 223, 225 of the central portion 205 whichcould degrade the strength of central portion 205 and increase theprobability of breakage when central portion 205 is bent such as whenrolled onto storage spool 185. Moreover, the lateral guides 143, 145 mayengage the glass ribbon 103 as it is being bent about the axis 217transverse to the travel direction 112 of the glass ribbon 103. Bendingthe glass ribbon 103 over the bending support member 135 can increasethe rigidity of the glass ribbon 103 throughout the bend. As such, thelateral guides 143, 145 can apply lateral forces to the glass ribbon 103in a bent condition as the glass ribbon 103 passes over the bendingsupport member 135. The forces 213, 215 applied by the lateral guides143, 145 are therefore less likely to buckle or otherwise disturb thestability of the glass ribbon profile when laterally aligning as theglass ribbon 103 passes over the bending support member 135.

The edge separation apparatus can further include a cutting zone 147downstream from the bending zone 125. In one example, the edgeseparation apparatus 101 a may include a cutting support member 149configured to bend the glass ribbon 103 in the cutting zone 147 toprovide a bent target segment 151 with a bent orientation in the cuttingzone 147. Bending the target segment 151 within the cutting zone 147 canhelp stabilize the glass ribbon 103 during the cutting procedure. Suchstabilization can help prevent buckling or disturbing the glass ribbonprofile during the procedure of severing at least one of the opposededge portions 201, 203 from the central portion 205 of the glass ribbon103. The cutting zone produces an edge quality that possibly enables thecentral portion 205 to be bent at a radius of ≦500 mm, ≦300 mm, ≦200 mm,≦100 mm, or ≦50 mm.

The cutting support member 149, if provided, can comprise a non-contactcutting support member 149 designed to support the glass ribbon 103without touching the opposed sides 139, 141 of the glass ribbon 103. Forexample, the non-contact cutting support member 149 can comprise one ormore curved air bars configured to provide a cushion of air spacebetween the glass ribbon 103 and the cutting support member 149 toprevent the central portion 205 of the glass ribbon 103 from contactingthe cutting support member 149.

In one example, the cutting support member 149 can be provided with aplurality of passages 150 configured to provide positive pressure portssuch that an air stream can be forced through the positive pressureports toward the bent target segment 151 to create an air cushion for anoncontact support of the bent target segment 151. Optionally, theplurality of passages 150 can include negative pressure ports such thatan air stream can be drawn away from the bent target segment 151 tocreate a suction to partially counteract the force from the air cushioncreated by the positive pressure ports. A combination of positive andnegative pressure ports can help stabilize the bent target segment 151throughout the cutting procedure. Indeed, the positive pressure portscan help maintain a desired air cushion height between the centralportion 205 of the glass ribbon 103 and the cutting support member 149.At the same time, the negative pressure ports can help pull the glassribbon toward the cutting support member 149 to prevent the glass ribbon103 from undulating and/or prevent portions of the bent target segment151 from floating away when traversing over the cutting support member149 in the travel direction 112.

Providing a bent target segment 151 in the cutting zone 147 can alsoincrease the rigidity of the glass ribbon 103 throughout the cuttingzone 147. Increasing the rigidity of the glass ribbon 103 throughout thecutting zone 147 can help reduce changes in orientation due to naturalshape variation of the incoming ribbon 103 which can produce undesirablevariation in the cutting process. Increasing the rigidity of the glassribbon 103 throughout the cutting zone 147 can also reduce the impact ofmechanical perturbations and vibrations on the cutting process. Also, asshown in FIG. 3, optional lateral guides 219, 221 can apply lateralforces to the glass ribbon 103 in a bent condition as the glass ribbon103 passes over the cutting support member 149 within the cutting zone147. Forces 223, 225 applied by the lateral guides 219, 221 aretherefore less likely to buckle or otherwise disturb the stability ofthe glass ribbon profile when laterally aligning as the glass ribbon 103passes over the cutting support member 149. The optional lateral guides219, 221 can therefore be provided to fine tune the bent target segment151 at the proper lateral orientation along a direction of the axis 217transverse to the travel direction 112 of the glass ribbon 103.

As set forth above, providing the bent target segment 151 in a bentorientation within the cutting zone 147 can help stabilize the glassribbon 103 during the cutting procedure. Such stabilization can helpprevent buckling or disturbing the glass ribbon profile during theprocedure of severing at least one of the opposed edge portions 201,203. Moreover, the bent orientation of the bent target segment 151 canincrease the rigidity of the target segment to allow optional fine tuneadjustment of the lateral orientation of the bent target segment 151. Assuch, relatively thin glass ribbons 103 can be effectively stabilizedand properly laterally oriented without contacting the pristine opposedfirst and second sides 141, 139 of the central portion 205 of the glassribbon 103 during the procedure of severing at least one of the opposededge portions 201, 203 from the central portion 205 of the glass ribbon103.

Increased stabilization and rigidity of the bent target segment 151 ofthe glass ribbon 103 can be achieved by bending the target segment toinclude an upwardly convex surface and/or an upwardly concave surfacealong a direction of the axis 217 transverse to the travel direction112. For example, as shown in FIG. 1, the bent target segment 151includes a bent orientation with an upwardly facing convex surface 152configured to bend the glass ribbon 103 in the cutting zone 147 toachieve the illustrated bent orientation. Although not shown, furtherexamples may include supporting the target segment 151 with an upwardlyfacing concave surface configured to allow the bent target segment toachieve an upwardly facing concave surface.

The edge separation apparatus 101 a can further include a wide range ofcutting devices configured to sever the edge portions 201, 203 from thecentral portion 205 of the glass ribbon 103. In one example, as shown inFIG. 1, one example glass cutting device 153 can include an opticaldelivery apparatus 155 for irradiating and therefore heating a portionof the upwardly facing surface of the bent target segment 151. In oneexample, optical delivery apparatus 155 can comprise a radiation sourcesuch as the illustrated laser 161 although other radiation sources maybe provided in further examples. The optical delivery apparatus 155 canfurther include a circular polarizer 163, a beam expander 165, and abeam shaping apparatus 167.

The optical delivery apparatus 155 may further comprise optical elementsfor redirecting a beam of radiation (e.g., laser beam 169) from theradiation source (e.g., laser 161), such as mirrors 171, 173 and 175.The radiation source can comprise the illustrated laser 161 configuredto emit a laser beam having a wavelength and a power suitable forheating the glass ribbon 103 at a location where the beam is incident onthe glass ribbon 103. In one embodiment, laser 161 can comprise a CO₂laser although other laser types may be used in further examples.

The laser 161 may be configured to initially emit the laser beam 169with a substantially circular cross section (i.e. the cross section ofthe laser beam at right angles to the longitudinal axis of the laserbeam). The optical delivery apparatus 155 is operable to transform laserbeam 169 such that the beam has a significantly elongated shape whenincident on glass ribbon 103. As shown in FIG. 3, the elongated shapecan produce an elongated radiation zone 227 that may include theillustrated elliptical footprint although other configurations may beprovided in further examples. The elliptical foot print can bepositioned on the upwardly facing convex or concave surface of the benttarget segment 151. Heat from the elongated radiation zone 227 cantransmit through the entire thickness of the glass ribbon 103.

The boundary of the elliptical footprint can be determined as the pointat which the beam intensity has been reduced to 1/e² of its peak value,wherein “e” is the base of the natural logarithm. The laser beam 169passes through circular polarizer 163 and is then expanded by passingthrough beam expander 165. The expanded laser beam then passes throughbeam shaping apparatus 167 to form a beam producing the ellipticalfootprint on a surface of the bent target segment 151. The beam shapingapparatus 167 may, for example, comprise one or more cylindrical lenses.However, it should be understood that any optical elements capable ofshaping the beam emitted by laser 161 to produce an elliptical footprinton the bent target segment 151 may be used.

The elliptical footprint can include a major axis that is substantiallylonger than a minor axis. In some embodiments, for example, the majoraxis is at least about ten times longer than the minor axis. However,the length and width of the elongated radiation zone are dependent uponthe desired severing speed, desired initial defect size, thickness ofthe glass ribbon, laser power, material properties of the glass ribbon,etc., and the length and width of the radiation zone may be varied asneeded.

As further shown in FIG. 1, the example glass cutting device 153 canalso include a coolant fluid delivery apparatus 159 configured to coolthe heated portion of the upwardly facing surface of the bent targetsegment 151. The coolant fluid delivery apparatus 159 can comprise acoolant nozzle 177, a coolant source 179 and an associated conduit 181that may convey coolant to the coolant nozzle 177. As shown in FIG. 1,the forced fluid cooling can occur on the same side of the glass as theincident heating source. As shown, the forced fluid cooling and incidentheating sources can be applied to the upper surface of the glassalthough they can both be applied to the lower surface in furtherexamples. Still further, the heat source and cooling source can beincident on opposite surfaces of the glass ribbon. For example, one ofthe forced fluid cooling source and the heating source can be positionedto act on an upper surface of the ribbon while the other of the forcedfluid cooling source and the heating source acts on the lower surface ofthe ribbon. In such a configuration, the oppositely located cooling andheating sources can be counter-propagating.

With reference to FIG. 1, the coolant nozzle 177 can be configured todeliver a coolant jet 180 of coolant fluid to the upwardly facingsurface of the bent target segment 151. The coolant nozzle 177 can havevarious internal diameters to form a cooling zone 229 (see FIG. 3) of adesired size. As with elongated radiation zone 227, the diameter ofcoolant nozzle 177, and the subsequent diameter of coolant jet 180, maybe varied as needed for the particular process conditions. In someembodiments, the area of the glass ribbon immediately impinged upon bythe coolant (cooling zone) can have a diameter shorter than the minoraxis of the radiation zone 227. However, in certain other embodiments,the diameter of the cooling zone 229 may be larger than the minor axisof elongated radiation zone 227 based on process conditions such asspeed, glass thickness, material properties of the glass ribbon, laserpower, etc. Indeed, the (cross sectional) shape of the coolant jet maybe other than circular, and may, for example, have a fan shape such thatthe cooling zone forms a line rather than a circular spot on the surfaceof the glass ribbon. A line-shaped cooling zone may be oriented, forexample, perpendicular to the major axis of elongated radiation zone227. Other shapes may be beneficial.

In one example, the coolant jet 180 comprises water, but may be anysuitable cooling fluid (e.g., liquid jet, gas jet or a combinationthereof) that does not permanently stain or damage the upwardly facingsurface of the bent target segment 151 of the glass ribbon 103. Thecoolant jet 180 can be delivered to a surface of the glass ribbon 103 toform the cooling zone 229. As shown, the cooling zone 229 can trailbehind the elongated radiation zone 227 to propagate an initial defectformed by aspects of the disclosure described more fully below.

Although not shown, in some configurations coolant fluid deliveryapparatus 159 may not be required to perform the cutting operation. Forexample, heat transfer to the environment (e.g., air flowing through thesupport member 149 and natural convection of the moving web) may provideall the cooling that is required to sustain the cutting process withoutthe presence or operation of the coolant fluid delivery apparatus 159.

The combination of heating and cooling with the optical deliveryapparatus 155 and the coolant fluid delivery apparatus 159 caneffectively sever the edge portions 201, 203 from the central portion205 while minimizing or eliminating undesired residual stress,microcracks or other irregularities in the opposed edges 223, 225 of thecentral portion 205 that may be formed by other severing techniques.Moreover, due to the bent orientation of the bent target segment 151within the cutting zone 147, the glass ribbon 103 can be properlypositioned and stabilized to facilitate precise severing of the opposededges 223, 225 during the severing process. Still further, due to theconvex surface topography of the upwardly facing convex support surface,the edge portions 201, 203 can immediately travel away from the centralportion 205, thereby reducing the probability that the edge portionswill subsequently engage (and therefore damage) the pristine first andsecond sides 141, 139 and/or the high quality opposed edges 223, 225 ofthe central portion 205. As shown in FIG. 1, two curved support members135, 149 may be provided. In further examples, a single curved supportmember may be provided, thereby eliminating the need for a second curvedsupport member.

Turning back to FIG. 1, the edge separation apparatus 101 a may includestructures configured to further process the severed edge portions 201,203 and/or the central portion 205 of the glass ribbon 103 downstreamfrom the cutting zone 147. For example, one or more glass ribbonchoppers 183 may be provided to chop, shred, break or otherwise compactthe trim segments for disposal or recycling.

The central portion 205 of the glass ribbon 103 can be further processedby cutting into glass sheets for incorporation into optical components.For example, the apparatus 101 may include the apparatus 101 b forsevering a glass ribbon described more fully below to sever the centralportion 205 of the glass ribbon 103 along the axis 217 transverse to thetravel direction 112 of the glass ribbon 103. In addition, oralternative to the apparatus 101 b for severing a glass ribbon, thecentral portion 205 of the glass ribbon 103 can be coiled into a storageroll 185 for later processing. As shown, removing the edge portions 201,203 consequently removes the corresponding beads 207, 209. Removing thebeads reduces the minimum bend radius to allow the central portion 205of the glass ribbon 103 to be more efficiently wound into a storage roll185. As represented in FIG. 2, the central core 187 of the storage roll185 is significantly reduced when compared to the central core 189 ofthe coiled spool 124. As such, the diameter “D₂” of the storage roll 185of the central portion 205 is significantly smaller than the diameter“D₁” that would store the same length of pre-processed glass ribbon inthe coiled spool 124.

Still further shown in FIG. 1, the edge separation apparatus 101 a mayalso include further noncontact support members to guide at least thecentral portion 205 of the glass ribbon 103 downstream from the cuttingzone 147. For example, as shown, the apparatus can include a first airbar 188 and a second air bar 190 to guide the central portion 205 of theglass ribbon for final processing without contacting the surfaces. Twosupport members are illustrated although a single support member or morethan two support members may be provided in further examples. As furthershown, an optional support member 191 can also be provided to allow theedge portion to be guided to the glass ribbon chopper 183. The optionalsupport member 191 can optionally comprise an air bar or low frictionsurface to reduce binding and/or restricted movement as the edge portionproceeds to the glass ribbon choppers 183.

In some examples, the glass ribbon 103 may also travel directly from thesource 105 of glass ribbon to an apparatus 101 b for severing the glassribbon 103. Alternatively, as shown, the edge separation apparatus 101 amay optionally remove edge portions of the glass ribbon 103 at alocation upstream. Subsequently, the central portion 205 of the glassribbon 103 can travel with respect to the apparatus 101 b for eventualfinal processing of the glass ribbon. In some examples, the glass ribboncan be severed into appropriate severed lengths. In further examples, anundesired segment (e.g., segment of low quality) can be removed from theotherwise continuous length of high quality glass ribbon. In stillfurther examples, the glass ribbon can be stored on the illustratedstorage roll 185. In one example, the apparatus 101 b for severing theglass ribbon 103 can be used to switch between a full storage roll and anew storage roll without interrupting movement of the glass ribbon alongtravel direction 112.

FIG. 2 illustrates just one example of an apparatus 101 b that may beused to selectively sever the glass ribbon 103 although other apparatusmay be used in further examples. As shown in FIG. 2, the apparatus 101 bmay include a monitoring device 193 that may sense a characteristic ofthe glass ribbon 103 and send back a corresponding signal to acontroller 195. Characteristics can include, but are not limited to,optical quality, inclusions, cracks, inhomogeneous features, thickness,color, surface flatness or imperfections, and/or other features. In oneexample, the monitoring device 193 may comprise a quality control deviceconfigured to screen the glass ribbon, either continuously orperiodically, in an effort to ensure a high quality glass ribbon passingto be stored or further processed.

As further illustrated, the apparatus 101 b may further include a device197 configured to generate a predetermined flaw in the first side 141 ofthe glass ribbon 103. In one example, the device 197 can include theillustrated mechanical scoring device wherein a relatively sharp tip 301may be used to score the first side 141 of the glass ribbon 103. Infurther examples, the device 197 can comprise a laser or other deviceconfigured to introduce the predetermined flaw at the edge, sidesurface, or within a portion along the width of the glass ribbon 103.

As further illustrated in FIG. 6, the apparatus 101 b may optionallyinclude a support member 130 configured to emit fluid 132 to impact thefirst side 141 of the glass ribbon 103 to at least partially support aweight of a portion 103 a of the glass ribbon 103 within a severing zone134 while maintaining the portion 103 a of the glass ribbon 103 in afirst orientation. As shown, the first orientation can comprise asubstantially flat orientation that runs along the travel direction 112although the first orientation may be curved or form other travel pathsin further examples.

Examples of the apparatus 101 b for severing the glass ribbon 103 canfurther include a device 140 configured to temporarily bend the portion103 a of the glass ribbon 103 in a direction 146 toward the supportmember from the first orientation (e.g., shown in FIG. 6) to a severingorientation (e.g., shown in FIGS. 7 and 8) by applying a force to thesecond side 139 of the glass ribbon 103. The device 140 for temporarilybending the portion 103 a of the glass ribbon 103 can comprise a widerange of structures with various configurations.

FIG. 6 illustrates just one device 140 that may be used to temporarilybend the portion 103 a of the glass ribbon 103. The example device 140may include a fluid nozzle 142. As schematically shown in FIG. 5, thefluid nozzle 142 may extend along substantially the entire width of theglass ribbon 103. Furthermore, as shown, the nozzle 142 may have a widththat is substantially greater than the width of the glass ribbon 103.The nozzle 142, if provided, can be a continuous nozzle and/or aplurality of nozzles spaced apart from one another in a row across thewidth of the glass ribbon.

The nozzle 142 can include an orifice 144 designed to emit fluid, suchas gas, to impact the second side 139 of the glass ribbon 103 within thesevering zone 134. As shown in FIG. 2, the nozzle 142 can receivedpressurized fluid, such as gas, from a fluid source 136 by way of afluid manifold 138 configured to be controlled by the controller 195.

FIG. 12 illustrates yet another example of an apparatus 601 for severingthe glass ribbon 103. The apparatus 601 can include at least a firstroller 603 configured to apply a force to the second side 139 of theglass ribbon 103. The apparatus 601 can further include a second roller605 and a third roller 607 spaced from the second roller along a supportwidth “S.” The first roller 603 applies the force to the second side 139of the glass ribbon 103 along the support width “S” defined between thesecond roller 605 and the third roller 607. Optionally, an endless belt609 can be configured to rotate with the second roller 605 and the thirdroller 607. For example, the endless belt 609 can be mounted with thesecond roller 605 acting as one end roller and the third roller 607acting as the second end roller, wherein the rollers can be biased awayfrom each other to help maintain the endless belt 609 in tension.

As further shown in FIG. 12, the apparatus 601 can include a supportmember 611 that may support the portion 103 a of the glass ribbon in thefirst orientation shown in FIG. 12. In one example, the support membercan include passages to transfer fluid, such as gas, through thepassages to support the portion 103 a of the glass ribbon with a liquid(e.g., gas) cushion generated between the first side 141 and the supportmember 611.

In one example, there may be a plurality of support members 611 offsetrelative to one another along the width “W” of the support memberextending transverse to the travel direction 112. For example, as shownin FIG. 13, the support member 611 comprises three spaced supportmembers 611 a, 611 b, 611 c spaced from one another. Likewise, in suchexamples, a plurality of endless belts may be provided between each ofthe spaced support members. For example, as shown in FIG. 13, theendless belt 609 includes a first endless belt 609 a positioned betweenadjacent support members 611 a, 611 b and a second endless belt 609 bpositioned between adjacent support members 611 b, 611 c. As such, theportion 103 a of the glass ribbon 103 may be adequately supported in thefirst orientation shown in FIGS. 12 and 14 (i.e., by the fluid cushion)and the bent orientation shown in FIGS. 15 and 16.

In yet another example, the apparatus for severing the glass ribbon mayinclude an apparatus similar to FIGS. 6-10 but include at least oneroller, rather than the fluid nozzle 142, configured to apply the forceto the second side of the glass ribbon. In such an example, the roller(e.g., similar to the first roller 603 discussed above) can rotate whiletemporarily bending the portion of the glass ribbon in the directiontoward the support member. As such, rather than the non-contact fluidnozzle 142, a contact roller may be provided that temporarily bends theportion of the glass ribbon in the direction toward the support membersimilar to that shown in FIGS. 7-9. At the same time, as shown in FIGS.7-9 upstream and downstream support members can provide a contact-freesupport of the first side of the glass ribbon with corresponding fluidcushions provided by the support members.

As described above, the glass ribbon 103 can be severed by any number ofmeans. After the glass ribbon 103 is severed as shown in FIG. 11, theglass ribbon is separated into an upstream web 631 and a downstream web633. The upstream web 631 comprises an upstream edge portion 635including an upstream severed edge 637. The downstream web 633 comprisesa downstream edge portion 639 including a downstream severed edge 641.It can be advantageous to create a gap 683 between the upstream web 631and the downstream web 633. The gap 683 can help facilitate storage roll501, 503 change without changing the process speed of the apparatus 101.Additionally, the gap 683 can also help reduce or eliminate damage tothe glass ribbon 103 created by glass-to-glass contact between thedownstream severed edge 637 and the upstream severed edge 641.

Processing glass substrates in sheet or roll form can include the use ofa handling tabs 651, 653 (e.g., see FIG. 3) located on the glass ribbon103 to aid in various processing steps. The handling tabs 651, 653 maybe provided on the edge portions 201, 203. For instance, the handlingtabs 651, 653 may have been previously applied and rolled into the spool124. Such handling tabs 651, 653 may be provided, for example to helpalign the glass ribbon in the spool 124 and help space the pristinesurfaces of the glass ribbon wound in the spool 124. FIG. 3schematically illustrates the handling tabs 651, 653 adjacent the beads207, 209 for illustration purposes. While the handling tabs 651, 653 maybe provided on the beads, in addition or alternatively, the handlingtabs may also be provided on the edges 223, 225 of the central section205 of the glass ribbon 103 after the edge portions 201, 203 have beenremoved.

If provided, handling tabs 651, 653 can be placed on the glass ribbon tohelp reduce physical damage to the glass ribbon during handling. Inanother example, the handling tabs 651, 653 can help align layers ofglass ribbon 103 within storage rolls 501, 503 (e.g., see FIG. 11) sothat the edges of the roll remain aligned with respect to one anotherwhile spacing the pristine surfaces of the glass ribbon from one anotheras the glass ribbon 103 is rolled. In yet another example, the handlingtabs 651, 653 can be configured to permit glass ribbon 103 location andmanipulation without physical contact of one layer of the glass ribbon103 with an adjacent layer of the glass ribbon within the storage roll501, 503. Furthermore, the handling tabs 651, 653 can be removable.

As shown in FIG. 3 and mentioned previously, the handling tabs 651, 653can be applied to the glass ribbon 103 prior to the optional step ofedge separation. In addition or alternatively, the handling tabs 651,653 can be applied to the glass ribbon 103 after the optional edgeseparation. In another example, the handling tabs 651, 653 can beapplied to the glass ribbon 103 prior to being wound about glass ribbonsource 105 (e.g., FIG. 1), remain applied to the glass ribbon throughthe glass ribbon severing process, and then be wound with the glassribbon onto a storage roll 501, 503. In another example, the handlingtabs 651, 653 can be applied to the upstream web 631 and the downstreamweb 633 after the glass ribbon has been severed. FIG. 25 illustrates ahandling tab 651 attached to a first side edge 657 and a handling tab653 attached to a second side edge 659. Further examples can includeonly one of the handling tabs 651, 653 attached to one of the first sideedge 657 or the second side edge 659.

FIG. 25 shows one example of handling tabs 651, 653 located on the glassribbon 103. Handling tab 651 is shown attached to the first side edge657 and handling tab 653 is shown attached to the second side edge 659.Each of the handling tabs 651, 653 can include apertures 661 open at aninterior edge of the handling tab to expose the entire width of theglass ribbon 103 across its width, i.e., parallel to the direction ofaxis 217, which can be substantially perpendicular to the traveldirection 112 of the glass ribbon 103. Each of the apertures 661 canextend only partially across the handling tabs 651, 653, so that atleast a portion of the handling tabs 651, 653 is continuous along theglass ribbon 103. The apertures 661 can be said to resemble “mouseholes” in their appearance with an opening at an interior edge of thehandling tab to effectively reduce the transverse width of the tabacross the apertures 661 to expose a target area 663. As previouslydescribed, the handling tabs 651, 653 can be applied to the upstream web631 and the downstream web 633 after the glass ribbon has been severed.In this case, the apertures 661 are aligned with the sever line orresulting gap between the upstream web 631 and the downstream web 633.In another example, the handling tabs 651, 653 can be applied to theglass ribbon 103 prior to the severing operation. In this case, theapertures 661 allow the glass ribbon 103 to be severed across its entirewidth (e.g. in the target area 663) while maintaining a physicalconnection between the individual severed pieces of the glass ribbon103. The handling tabs 651, 653 can be removed entirely or can be cut atthe apertures 661 at a later time to enable separate processing of theupstream web 631 and the downstream web 633.

As shown in FIG. 17, the velocity of the glass ribbon 103 can becontrolled by sets of powered pinch rolls 665, 667. It is to beappreciated that pinch rolls are but one example of mechanismsconfigured to control the velocity of the glass ribbon 103, and anymechanism as is known in the art can be used. In one example, a set ofpinch rolls 665 can control the velocity of the upstream web 631, whileanother set of pinch rolls 667 can control the velocity of thedownstream web 633. Of course, any number of sets of pinch rolls 665,667 may be employed to control the velocity of the glass ribbon 103, anda controls system (not shown) can track which sets of pinch rolls 665,667 are in contact with the upstream web 631 and the downstream web 633in order to better control the glass ribbon 103 manufacturing process.

FIG. 20 illustrates an additional device that can be used to control thevelocity of at least a portion of the glass ribbon 103. For instance,the apparatus may include at least one accumulator such as an upstreamaccumulator and/or a downstream accumulator. For illustration purposes,FIG. 20 is a schematic representation of an upstream accumulator 673 anda downstream accumulator 675 although only one of the accumulators maybe provided in further examples. The upstream accumulator 673 can belocated on the upstream side of a severing zone 134, and the downstreamaccumulator 675 can be located on the downstream side of the severingzone 134. As a result, the upstream accumulator 673 and the downstreamaccumulator 675 can provide some control of the velocity of the upstreamweb 631 and the downstream web 633, respectively, by varying the pathlength of the upstream web 631 and the downstream web 633 as will bedescribed below. As shown, the accumulators 673, 675 may compriserollers that can selectively increase the travel path of portions of theglass ribbon to selectively create a gap as described below. In theillustrated example, each accumulator 673, 675 includes six rollersalthough more or less rollers may be used in further examples. Forinstance, in one example, three rollers may be provided with two rollerslocated above the glass ribbon 103 (e.g., the outer two rollers of thethree illustrated upper rollers) and a single roller located below theglass ribbon 103 (e.g., the center roller of the three illustrated lowerrollers). While rollers are shown, further examples can includeexpanding air bars or other structures configured to selectivelyincrease the travel path of portions of the glass ribbon to likewisecreate a gap during processing.

Methods of fabricating the glass ribbon 103 with the apparatus 101 thatcreates a gap between an upstream severed edge and a downstream severededge will now be described. As shown, in one example, the method caninclude use of the edge separation apparatus 101 a shown in FIG. 1. Inaddition or alternatively, the method can use an apparatus for severingthe glass ribbon (e.g., see apparatus 101 b in FIG. 2 or apparatus 601in FIG. 12, for example).

Turning to the example edge separation apparatus 101 a of FIG. 1, oneexample method can include the step of traversing the glass ribbon 103in a downward direction 121 relative to the source 105 through thedownward zone 123. As shown, the glass ribbon 103 can travelsubstantially vertically in the downward direction 121 although thedownward direction may be angled in further examples wherein the glassribbon 103 can travel at an inclined orientation in the downwarddirection. Also, if the glass ribbon 103 is supplied on a spool such as124, it may also traverse from the spool to the cutting unit in asubstantially horizontal direction. For example, the coiled spool 124and cutting zone may exist in nearly the same horizontal plane. Infurther examples, the spool may be positioned below the horizontaltravel plane and unwound horizontally or upwardly to traverse alongtravel direction 112. Similarly, if other methods of making the ribbonare used, for example a float process or an up-draw process, the ribbonmay travel in a horizontal, or upward direction as it travels from theforming source to the cutting unit and/or cutting zone.

The method can further include the step of bending the glass ribbon 103in the bending zone 125 downstream from the downward zone 123, whereinthe glass ribbon 103 includes the upwardly concave surface 127 throughthe bending zone 125. As shown, the lower portion 137 can besignificantly lower than the bent target segment 151 in the cutting zone147 although the lower portion 137 may be at substantially the sameelevation or even higher than the bent target segment in furtherexamples. Providing the lower portion 137 at a significantly lowerposition, as shown, can develop a predetermined amount of accumulatedglass ribbon prior to engaging the support members (e.g., support member135) of the edge separation apparatus 101 a. As such, vibrations orother disturbances upstream from the lower portion 137 may be absorbedby the accumulated glass ribbon within the bending zone. Moreover, theglass ribbon 103 may be drawn at a substantially constant or desiredpredetermined rate as it passes through the cutting zone 147 independentof how fast the glass ribbon 103 is being fed into the downward zone 123by the source 105. As such, providing an accumulation within the bendingzone 125 can allow for further stabilization of the glass ribbon 103within the cutting zone 147 while also allowing the glass ribbon 103 tobe passed through the cutting zone 147 at a substantially constant orpredetermined rate.

If provided, various techniques may be used to help maintain a desiredaccumulation of glass ribbon 103 within the bending zone 125. Forexample, a proximity sensor 129 or other device may be able to sense aposition of the accumulated ribbon to adjust the rate at which glassribbon is fed into the downward zone 123 by the source 105 to providethe appropriate accumulation of glass ribbon 103.

In further examples, the method can further include the step of bendingthe glass ribbon 103 downstream from the bending zone 125 to redirectthe glass ribbon to travel in the travel direction 112. As shown, thebending support member 135 may comprise a bent air bar designed toeffect the desired change of direction without contacting the centralportion 205 of the glass ribbon 103. Furthermore, the method can alsoinclude the optional step of orienting the glass ribbon 103 being bentwith the bending support member with the lateral guides 143, 145 to helporient the glass ribbon 103 in the correct lateral position relative tothe travel direction 112 of the glass ribbon 103.

The method can also include the step of traversing the glass ribbon 103into the cutting zone 147 downstream from the bending zone 125 and thenbending the glass ribbon 103 in the cutting zone 147 to provide the benttarget segment 151 with a bent orientation in the cutting zone 147.

As shown in FIG. 1, the glass ribbon 103 can be bent such that the bentorientation of the target segment 151 includes the upwardly facingconvex surface. In one example, the method can include the step ofsupporting the bent target segment 151 with the cutting support member149 comprising the illustrated curved air bar. As shown, the cuttingsupport member 149 can include an upwardly facing convex support surface152 configured to bend the target segment 151 to establish the upwardlyfacing convex surface.

As shown in FIG. 1, the method can further include the step of severingat least one of the edge portions 201, 203 from the central portion 205of the bent target segment 151 within the cutting zone 147. As shown inFIG. 3, the examples of the disclosure can include severing both of theedge portions 201, 203 from the central portion 205 although a singleedge portion may be severed from the central portion in furtherexamples. Moreover, as shown in FIG. 3, both of the edge portions 201,203 are severed simultaneously from the central portion 205 although oneof the edge portions may be severed before the other edge portion infurther examples.

The glass ribbon 103 may include edge beads 207, 209. Alternatively, theglass ribbon 103 may have edge portions 201, 203 that are free fromsubstantial edge beads or features. For example, the edge beads 207, 209may have been already removed in a previous cutting process or the glassribbon 103 may have been formed without significant edge bead features.Also, the included figures indicate that the separated edge portions201, 203 are disposed of or recycled. In another example, the separatededge portions form useable glass ribbon in addition to the centralportion 205 and can likewise be either cut into sheets or spooled asproduct. In this case, multiple cutting operations can exist across theglass ribbon width is it traverses through the cutting unit.

The step of severing can incorporate a wide range of techniques. Forexample, the edge portions 201, 203 can be severed from the centralportion 205 by way of the glass cutting device 153 that can include theillustrated optical delivery apparatus 155 and the coolant fluiddelivery apparatus 159.

One example of initiating the severing process can use a scribe or othermechanical device to create an initial defect (e.g., crack, scratch,chip, or other defect) or other surface defect at the site where theglass ribbon is to be severed. The scribe can include a tip although anedge blade or other scribe technique may be used in further examples.Still further, the initial defect or other surface imperfection may beformed by etching, laser impact, or other techniques. The initial defectmay be created at the edge of the ribbon or at an inboard location onthe ribbon surface.

The initial defect or surface imperfection can be initially formedadjacent a leading edge of the glass ribbon 103 traversing in the traveldirection 112. As shown in FIG. 3, the elongated radiation zone 227 maybe formed on the upwardly facing convex surface. As the elongatedradiation zone 227 is elongated in the travel direction 112, theradiation heats the region in proximity to the initial defect. Thecoolant jet 180 then contacts the cooling zone 229 to generate a crackat the initial defect that completely travels through the thickness “T₂”of the glass ribbon 103 due to the created tensile stress to sever thecorresponding edge portions 201, 203 from the central portion 205.

The severed opposed edge portions 201, 203 can be effectively removedwhile leaving the central portion 205 with high quality opposed edges223, 225 with reduced internal stress profiles, reduced cracks, or otherimperfections in the opposed edges 223, 225. As such, the centralportion 205 can be bent, such as wound in the storage roll 185 withoutcracking that may otherwise occur with reduced quality edges. Moreover,the higher quality edges can avoid scratching the central portion 205during coiling that might otherwise occur with edge portions includingglass shards or other imperfections. In addition, the edge portions 201,203 can likewise be optionally wound on a spool for use in differentapplications.

The method can further include the step of supporting the bent targetsegment 151 with the upwardly facing convex surface 152 of the cuttingsupport member 149. For instance, the bent target segment 151 can besupported by the convex surface 152 of the illustrated air bar whilesevering the edge portions 201, 203 from the central portion 205 of thebent target segment 151 within the cutting zone 147.

The method can still further include the step of coiling the centralportion 205 of the glass ribbon 103 into the storage roll 185 after thestep of severing. As such, the high quality central portion 205 of theglass ribbon may be efficiently coiled into a storage roll 185 forsubsequent shipping or processing into glass sheets. As shown in FIGS. 1and 3, the severed edge portion 201, 203 can be disposed of in a glassribbon chopper 183 although alternative methodologies may be employed touse the edge portions for other applications. In such examples, one orboth of the severed edge portions 201, 203 may be stored oncorresponding storage rolls for subsequent processing.

Example methods of severing a glass ribbon 103 across its width, i.e.,parallel to the direction of axis 217 will now be described. As shown,the method can begin with providing the source 105 of the glass ribbon103 with a pair of edge portions 201, 203 that may or may not includethe beads 207, 209. Optionally, the edge portions 201, 203 may besevered by way of the procedure discussed above although the edgeportions may not be removed in further examples.

As shown, the central portion 205 of the glass ribbon 103 includes afirst side 141 facing a first direction and a second side 139 facing asecond direction opposite the first direction. In one example, theapparatus 101 can sense the amount of glass ribbon that has been coiledon the storage roll 185 and/or sense a characteristic of the glassribbon 103 with the monitoring device 193.

If it is determined the glass ribbon should be severed across its width,the controller 195 can activate the device 197, such as the illustratedscribe or other mechanical device, to create an initial defect (e.g.,crack, scratch, chip, or other defect) with the point of the scribe tocreate a controlled and predetermined surface defect at the site wherethe glass ribbon is to be severed. The scribe can include a tip althoughan edge blade or other scribe technique may be used in further examples.Still further, the initial defect or other surface imperfection may beformed by etching, laser impact, or other techniques. The initial defectmay be created at the edge of the ribbon or at an inboard location onthe ribbon surface at a point along the width of the ribbon. In oneexample, the predetermined surface defect comprises a predetermined flawthat is generated by the device 197.

FIG. 4 illustrates the tip 301 engaging the first side 141 and moving indirection 303 to create the predetermined flaw 305 shown in FIG. 5. Asshown, in one example, the predetermine flaw 305 can be generated as alinear segment having a length substantially less than a width of thecentral portion of the glass ribbon defined between the pair of opposededge portions. In addition or alternatively, the predetermined flaw 305can be generated as a linear segment extending in a direction of a widthof the central portion 205 of the glass ribbon 103 defined between thepair of opposed edge portions. Although not shown, the predeterminedflaw 305 can extend across a substantial portion, such as the entirewidth of the central portion 205. However, as the glass ribbon 103continues to move in travel direction 112, a relatively small segmentmay be desired to provide a linear segment to control proper severing ofthe glass ribbon along the width.

FIG. 6 illustrates the portion 103 a of the glass ribbon 103 includingthe predetermined flaw 305 traversing to the severing zone 134downstream from the source 105 of the glass ribbon 103. As furthershown, fluid 132 being emitted from the support member 130 impacts thefirst side 141 of the glass ribbon 103 to at least partially support aweight of the portion of glass ribbon within the severing zone 134 whilemaintaining the portion of the glass ribbon in the first orientation. Asshown in FIG. 6, the first orientation can substantially provide theglass ribbon along a planar orientation that may be substantiallyparallel to the travel direction 112.

FIG. 7 illustrates the predetermined flaw 305 being traversed fartherdownstream along travel direction 112 wherein the portion 103 a of theglass ribbon 103 is temporarily bent in the direction 146 toward thesupport member 130. The portion 103 a can be temporarily bent, forexample, by applying a force to the second side 139 of the glass ribbon103. In one example, a roller may be used to apply a force to the secondside 139 of the glass ribbon. Alternatively, as shown, applying theforce can be achieved by impacting the second side 139 of the glassribbon 103 with fluid 401 emitting from the orifice 144 of the nozzle142. Using a fluid to bend the glass ribbon can be desirable to preventscratching or otherwise damaging the glass ribbon that may otherwiseoccur with mechanical contact configurations.

As shown, the portion 103 a includes two parallel parts 402 a, 402 bthat extend along the same plane although the two parts 402 a, 402 b maynot be parallel in further examples and/or may extend along differentplanes. As shown, the orientation of the parts 402 a, 402 b can beoriented by supporting them with a support member 130. Moreparticularly, the first part 402 a can be supported by an upstreamsupport member 404 a, and the second part 402 b can be supported by adownstream support member 404 b. For instance, as shown the supportmembers 404 a, 404 b can comprise air bars configured to emit fluid 132,such as gas, to provide respective air cushions. Indeed, the upstreamsupport member 404 a can place a first support air cushion between theupstream support member 404 a and the first part 402 a of the portion103 a of glass ribbon 103. Likewise, the downstream support member 404 bcan place a second support air cushion between the downstream supportmember 404 b and the second part 402 b of the portion 103 a of glassribbon 103. As such, impacting the first side 141 of the glass ribbon103 with fluid emitting from each of the upstream support member 404 aand the downstream support member 404 b can provide respective gascushions that at least partially support a weight of the portion 103 aof glass ribbon 103 at respective upstream and downstream positions.Providing support with corresponding air cushions can help position theglass ribbon 103 for severing without touching the pristine surfaces ofthe glass ribbon. As such, scratching or other damage to the pristinesurfaces can be avoided.

As further illustrated in FIG. 7, the portion 103 a of the glass ribbon103 includes a target segment 402 c that can be defined between theupstream support member 404 a and the downstream support member 404 b.As shown in FIG. 6, the upstream support member 404 a and the downstreamsupport member 404 b can maintain the target segment 402 c of the glassribbon 103 in the first orientation within the severing zone 134.Moreover, as shown, at least a portion of the target segment 402 c canbe substantially free from support by the gas cushions of the supportmembers 404 a, 404 b.

As shown in FIG. 7, the method can further include the step oftemporarily bending the target segment 402 c of the glass ribbon 103 inthe direction 146 toward the support member 130 from the firstorientation to a severing orientation with a force generated byimpacting the second side 139 of the glass ribbon 103 with fluid 401emitting from the fluid nozzle 142. Optionally, the method can includethe step of increasing the rate that fluid is being emitted from atleast one of the support members 404 a, 404 b, such as both supportmembers, to at least partially counteract the force generated byimpacting the second side of the glass ribbon with fluid emitting fromthe fluid nozzle.

Once bent, the second side 139 has an upwardly concave portion providedbetween the two parts 402 a, 402 b of the portion 103 a of glass ribbon103. As such, the lower side of the target segment 402 c is placed intension. FIG. 8 shows the portion 103 a further traversing in traveldirection 112 such that the predetermined flaw 305 enters in the targetsegment 402 c and is placed in tension. FIG. 9 demonstrates the step ofsevering the central portion 205 of the glass ribbon 103 between theopposed edge portions at the predetermined flaw 305 located within thesevering zone 134. As can be seen from FIGS. 7 and 8, the upwardlyconcave portion is provided downstream of the predetermined flaw 305.Then, as the glass ribbon 103 travels in the travel direction 112, thepredetermined flaw 305 travels to the upwardly concave portion, and asit travels through that upwardly concave portion, the ribbon 103 issevered across its width at the point of the predetermined flaw 305. Itwould be difficult, on a traveling ribbon, to form an upwardly concaveportion exactly at the predetermined flaw. Accordingly, forming theupwardly concave portion first, and allowing the flaw to travel to thatportion facilitates severing the ribbon across its width. Additionally,or alternatively, forming the upwardly concave portion in the severingzone 134 and allowing the flaw to travel to the upwardly concave portioneliminates the need for a separate accumulator or stoppage of the ribbon103 in order to sever the ribbon 103 across its width.

If there are any constraints in the travel direction 112 upon the motionof the glass ribbon 103, they can be controlled during the severingprocess to allow formation of the curvature that places the lower sideof the target segment 402 c in tension. If, for example, a set of drivenpinch rolls were located near the lateral guides 143, 145, in FIG. 3,the length of the center section 205 may be influenced. In order toassist bending the glass ribbon 103, relative speed in the traveldirection 112 between the driven pinch rolls and the downstream takeupdevice (ex. central core 187 in FIG. 2) can allow for a slightaccumulation of length within the severing zone 134.

In addition, the apparatus may include a mechanism to facilitatemovement of the glass ribbon along the travel direction 112. Forexample, in some embodiments, the central core 187 may be driven torotate to help facilitate movement of the glass ribbon 103 along thetravel direction 112. In addition, or alternatively, a set of driverollers may facilitate movement of the glass ribbon. Providing a set ofdrive rollers, for example, can help facilitate movement of the glassribbon together with the severed end 409 that is no longer connected tothe central core 187 after severing. As such, the drive rollers cancontinue to move the severed end 409 along to be wound on to anothercentral core 187 after switching the storage rolls. The drive rollerscan be provided at various locations. For instance, the lateral guides143, 145 may be provided as driven rollers to help drive the glassribbon along the travel direction 112 although the driven rollers may beprovided at alternative locations in further examples.

FIGS. 9 and 10 demonstrate the step of returning the target segment 402c of the glass ribbon 103 to the first orientation by removing the forcebeing applied by the fluid nozzle 142. For example, once the flow offluid from the nozzle is stopped, the flow of fluid from the supportmember 130 can act against the glass ribbon to restore the glass ribbonto the first orientation, particularly as the severed area 406 travelsup into a linear support region of the second support member 404 b. Asshown, the downstream support member 404 b can include a leading endwith a convex support surface 407. The convex support surface 407, ifprovided, can inhibit obstruction of the severed end 409 of the glassribbon 103 after the step of severing.

FIG. 12 illustrates another apparatus 601 wherein the first roller 603is designed to provide the force to bend the glass ribbon. Providing aroller that rotates can minimize friction and damage to the surface thatwill likely occur due to the necessary mechanical engagement between theroller and the glass ribbon. Alternatively, driving the first roller 603to match the speed of the glass ribbon 103 can further reduce frictionand damage to the surface. The first roller 603 can bend the glassribbon temporarily, thereby minimizing the length of glass ribbon thatis contacted by the roller. As such, the first roller 603 may only betemporarily moved to bend the glass ribbon shortly before orsubstantially when the severing is to occur.

FIG. 14 shows the predetermined flaw 305 approaching the severing zone134 wherein the portion 103 a of the glass ribbon 103 including thepredetermined flaw 305 in the first orientation. This orientation may bemaintained, for example, by the support member 611 configured to emitfluid to contact the first side 141 to provide a support cushion.

FIG. 15 shows the roller 603 being moved in direction 801 to apply aforce to the second side 139 of the glass ribbon 103. As shown, theroller 603 rotates while temporarily bending the portion of the glassribbon in the direction 801 toward the support member 611. In someexamples, the air cushion generated by the support member 611 can causethe support member 611 to act against the bias of springs 803 and movein the direction 801 to avoid contacting the glass ribbon 103. As shownin FIG. 13, three spaced support members 611 a, 611 b, 611 c can, insome examples, be independently supported such that the support members611 a, 611 b, 611 c can each move downward to avoid contacting the glassribbon when bending the glass ribbon with the roller 603.

As further shown in FIG. 15, once the roller 603 is moved in direction801, the first side 141 of the glass ribbon 103 can be supported withthe second roller 605 and the third roller 607. Indeed, the first side141 of the glass ribbon 103 can be supported along the support width“S”. As shown, the first roller 603 applies the force to the second side139 of the glass ribbon 103 along the support width “S” defined betweenthe second roller 605 and the third roller 607. As such, a three pointbending configuration may be provided to help bend the ribbon traversingalong travel direction 112 through a bend similar to the bendillustrated in FIGS. 7 and 8.

Optionally, the endless belt 609 can be provided to rotate with thesecond roller 605 and the third roller 607 and the endless belt 609temporarily engages the first side 141 of the glass ribbon 103.Providing the endless belt 609 can help support the portion 103 a of theglass ribbon 103 as it traverses through the bend. Moreover, the endlessbelt 609 can help redirect the severed area 406 through the bend andultimately back to the first orientation shown in FIG. 14.

As shown in FIG. 13, the endless belt 609 can comprise two or more belts609 a, 609 b to provide adequate support across the width “W” of theglass ribbon 103. Pressing the first roller 603 in direction 801consequently bends the travel path of the endless belt 609 as shown inFIGS. 15 and 16. The belt can be substantially flexible and resilient toallow the belt to stretch to accommodate the increased overall beltlength resulting from the bent travel path if the second and thirdrollers 605, 607 remain at the same spacing relative to one another.Alternatively, as shown, the second and third rollers 605, 607 may beprovided with corresponding springs 613 a, 613 b that allow the secondand third rollers 605, 607 to be biased together, against the force ofthe springs, in corresponding directions 615 a, 615 b. In such anexample, the overall length of the endless belt 609 may remainsubstantially the same, wherein the second and third rollers 605, 607move toward each other to accommodate the bend of the travel path.

Once the portion 103 a of the glass ribbon 103 is severed along thepredetermined flaw 305, the first roller 603 can be retracted such thatthe first, second and third rollers do not apply a force to the glassribbon and the gas cushions from the support member 611 can againmaintain the portion of the glass ribbon in the first orientation asshown in FIG. 14. Consequently, the springs 613 a, 613 b, if provided,can bias the second and third rollers 605, 607 away from one anothersuch that the upper segment of the endless belt again achieves thelinear profile illustrated in FIG. 14. Moreover, as the portion 103 a isrepositioned from the bent orientation to the first orientation, thesprings 803 again bias the portion 103 a to be positioned above, and outof contact with the endless belt 609. As such, as shown in FIG. 14, theendless belt 609 does not engage the glass ribbon 103 in the firstorientation. Rather, the air cushion provided by the support member 611can be designed to provide the necessary support to the glass ribbon tomaintain the first orientation.

It will therefore be appreciated that the roller 603 can providetemporary bending of the portion 103 a of the glass ribbon including thepredetermined flaw 305 for a brief period of time. As such, bending canbe achieved to the extent necessary to sever the glass ribbon at thepredetermined flaw 305. Moreover, the first orientation may be achievedshortly after severing, wherein the glass ribbon is again supportedwithout mechanically engaging objects that may otherwise scratch orotherwise damage the glass ribbon.

The method can also include steps to create a gap between an upstreamsevered edge and a downstream severed edge. One example method canincrease a relative velocity of a downstream edge portion with respectto an upstream edge portion to create the gap between the upstreamsevered edge and the downstream severed edge. For illustration purposes,FIG. 17 schematically shows gauges 687, 689 displaying a velocity of theglass ribbon 103 at each set of pinch rolls 665, 667. The method furtherincludes severing the glass ribbon 103 along a direction transverse tothe travel direction 112. Severing the glass ribbon 103 can beaccomplished by any of the methods described above. In one example, thesevering operation can be initiated in response to a storage rollreaching a predetermined storage capacity as shown in FIG. 11. Sensors505 can send a signal to the controller 195 based upon the weight of thefirst storage roll 501 or the second storage roll 503. Upon receipt of asignal indicating a storage roll 501, 503 is at capacity, the controller195 can then initiate the severing operation. Additionally, oralternatively, the sensors 505 can send a signal to the controller 195based upon a length of the glass ribbon 103 that has been wound aroundthe storage roll 501, 503.

This severing operation divides the glass ribbon 103 into twocomponents; the upstream web 631 and the downstream web 633. As is bestseen in FIG. 18, the upstream web 631 comprises the upstream edgeportion 635 including the upstream severed edge 637. Similarly, thedownstream web 633 comprises the downstream edge portion 639 includingthe downstream severed edge 641. It is often advantageous to develop aglass web separation by forming a gap 683 between the upstream severededge 637 and the downstream severed edge 641. The gap 683 can facilitateease of transfer of the upstream web portion to a second storage rollwithout changing the linear velocity of the glass ribbon in upstreamlocations of the manufacturing process. The gap can also help eliminateand/or reduce damage that may otherwise result from two severed edges ofthe glass contacting each other during glass ribbon manufacturingprocesses. Indeed, the gap can help prevent abutting engagement betweenthe severed edges. The gap can also help prevent one severed edge fromriding over (or under) the other edge, thereby possibly creating cracks,breaks and/or other edge or surface imperfections in the glass ribbon.As such, creating the gap can help protect the upstream and downstreamedge portions of the glass ribbon without interruption of the glassribbon process. In one example, the gap can help protect the upstreamand downstream edge portions of the glass ribbon in order to allow rollto roll processing of glass ribbon without damage to the glass ribbonand without interrupting the flow of the glass ribbon through variousprocessing locations.

One method of creating the gap 683 can include increasing the relativevelocity of the downstream edge portion 639 with respect to the upstreamedge portion 635 to create the gap 683 between the downstream severededge 641 and the upstream severed edge 637. FIG. 18 illustrates a stepof increasing the velocity of the downstream edge portion 639 to providethe increased relative velocity of the downstream edge portion 639 withrespect to the upstream edge portion 635. A readout on gauge 687represents the velocity of the upstream web 631 as it is moved throughthe apparatus 101 with the pinch rolls 665. A readout on gauge 689 showsan increased velocity of the downstream web 633, thereby increasing therelative velocity of the downstream edge portion 639 with respect to theupstream edge portion 635. This difference in relative velocitiescreates a gap 683 between the downstream severed edge 641 and theupstream severed edge 637. In one example, the velocity of thedownstream edge portion 639 can be returned to the velocity of theupstream edge portion 635 at a time when the gap 683 has reached adesired width. This change in velocity of the downstream edge portion639 can be termed a “jog.” Alternatively, the described velocity changecontrolled by the pinch rolls 665 can be controlled by the speed of oneof the storage rolls 501, 503.

Turning to FIG. 19, another method of increasing the relative velocityof the downstream edge portion 639 with respect to the upstream edgeportion 635 to create a gap 683 between the downstream severed edge 641and the upstream severed edge 637 is shown. This method includes thestep of decreasing the velocity of the upstream edge portion 635 toprovide the increased relative velocity of the downstream edge portion639 with respect to the upstream edge portion 635. A readout on gauge687 represents the velocity of the upstream web 631 as it is movedthrough the apparatus 101 with the pinch rolls 665. A readout on gauge687 shows an decreased velocity of the upstream web 631, therebyincreasing the relative velocity of the downstream edge portion 639 withrespect to the upstream edge portion 635. This difference in relativevelocities creates a gap 683 between the downstream severed edge 641 andthe upstream severed edge 637. In one example, the velocity of theupstream edge portion 635 can be returned to the velocity of thedownstream edge portion 639 at a time when the gap 683 has reached adesired width.

In further examples of the method, the previously described accumulators673, 675 may be optionally employed in the step of increasing therelative velocity of the downstream edge portion 639 with respect to theupstream edge portion 635 to create a gap 683 between the downstreamsevered edge 641 and the upstream severed edge 637. As shown in FIG. 21,a set of guide rollers in the downstream accumulator 675 is moved in thedirection of arrow 695 to create a longer travel path for the downstreamweb 633. As such, an amount of the downstream web 633 is collected bythe downstream accumulator 675 to increase the velocity of thedownstream edge portion 639. If the speed at which the downstream web633 is moved through apparatus 101 remains constant, then the longertravel path will tend to increase the velocity of the downstream edgeportion 639. The difference in relative velocity between the downstreamedge portion 639 with respect to the upstream edge portion 635 createsthe gap 683 between the downstream severed edge 641 and the upstreamsevered edge 637.

Similarly, as shown in FIG. 22, a set of guide rollers in the upstreamaccumulator 673 is moved in the direction of arrow 697 to create alonger travel path for the upstream web 631. As such, an amount of theupstream web 631 is collected by the upstream accumulator 673 todecrease the velocity of the upstream edge portion 635. If the speed atwhich the upstream web 631 is moved through apparatus 101 remainsconstant, then the longer travel path will tend to decrease the velocityof the upstream edge portion 635. The difference in relative velocitybetween the downstream edge portion 639 with respect to the upstreamedge portion 635 creates the gap 683 between the downstream severed edge641 and the upstream severed edge 637.

In another example of the method, the gap 683 between the downstreamsevered edge 641 and the upstream severed edge 637 can facilitate easeof transfer of glass ribbon 103 flow from a first storage roll 501 to asecond storage roll 503 as seen in FIG. 11. As shown, the downstream web633 is wound on the first storage roll 501. A sensor 509 can detect thegap 683 and communicate the existence of the gap to the controller 195.The controller 195 can then initiate a path change for the upstream web631. In one example, the upstream web can then be guided toward thesecond storage roll 503 between a second storage roll support 404 c anda first storage roll support 404 d. The upstream edge portion 635 of theupstream web 631 is introduced to the second storage roll 503 to beginwinding the upstream web 631 on the second storage roll 503. It is to beappreciated that any method of changing the flow of the upstream web 631to the second storage roll 503 can be used. As the second storage roll503 reaches capacity, the steps can be repeated to introduce thefollowing severed glass web section to the first storage roll 501.

Returning to FIG. 25, the glass ribbon 103 can include a width 701extending transverse to the travel path between a first side edge 657and a second side edge 659. At least one of the first side edge 657 orsecond side edge 659 includes a handling tab 651, 653. The handling tabsinclude a mounting portion including an aperture 661 configured toexpose the entire respective first side edge 657 or the second side edge659 within the target area 663. In one example of the method, the stepof severing the glass ribbon 103 includes severing the glass ribbon 103through the at least one of the first side edge 657 or the second sideedge 659 within the target area 663.

Another example method of developing a glass web separation between theupstream web 631 and the downstream web 633 is shown in FIG. 23. Themethod includes severing the glass ribbon 103 at a first location 707transverse to the travel path as represented by travel direction 112. Asan example, the direction transverse to the travel path can besubstantially similar to the direction of axis 217 shown in FIG. 3. Themethod further includes severing the glass ribbon 103 at a secondlocation 709 transverse to the travel path. The first and secondsevering operations create a segment of glass ribbon 713 that is severedfrom an upstream web 631 including an upstream severed edge 637 and adownstream web 633 including a downstream severed edge 641. Removing thesegment of the glass ribbon 713 creates a gap 683 between the upstreamsevered edge 637 and the downstream severed edge 641. In one example,the first sever path is substantially parallel to the second sever path.

An example method can also include directing the upstream severed edge637 along a second travel path 721 to create the gap 683 between theupstream severed edge 637 and the downstream severed edge 641.Introduction of the upstream web 631 to the second travel path 721 canoccur within the severing zone 134. The second travel path 721 can leadto the second storage roll 503 (as shown in FIG. 11) where the upstreamweb 631 can be introduced to the second storage roll 503 for windingabout the second storage roll 503.

The described methods of developing a glass web separation between theupstream web 631 and the downstream web 633 can be beneficial forvarious processing techniques. In one example, the methods of severingcan be useful to allow continuous traversing of the glass ribbon alongtravel direction 112 or other directions without having to interruptmovement of the glass ribbon. In one example, the methods of severingcan be used to allow continuous storage of glass ribbon on storagerolls. For example, the methods of developing a glass web separation canbe used during a step of switching between storing a portion of theglass ribbon on a first storage roll and storing another portion of theglass ribbon on a second storage roll.

FIG. 11 illustrates one example of switching between a first storageroll 501 and a second storage roll 503. The method of switching betweenrolls is illustrated with the severing method including the fluid nozzle142 with the understanding that the method of switching can also be usedwith the severing method including the roll mechanism illustrated inFIGS. 12-16. As shown in FIG. 11, a sensor 505, such as the illustratedscale may be used to measure the amount of glass ribbon that has beencoiled on the storage roll. The controller 195 can be designed toinitiate a severing command once a predetermined amount of glass ribbonhas been stored on the roll. Once severed, for example, by one of thetechniques discussed above, the controller 195 can alter the path of theglass ribbon 103 from a path leading to the first storage roll 501 to apath leading to the second storage roll 503 that may be loaded withsubsequent glass ribbon (e.g. the upstream web 631). As such, thestorage rolls 501, 503 can be operated sequentially without interruptionof the continuous glass ribbon being processed, or a change in operatingspeed. It is to be appreciated that FIG. 11 represents a simplifiedschematic of the storage roll switching process. Additional equipmentsuch as vacuum belts and pinner devices can be included.

In addition or alternatively, the methods of severing can be used toremove an undesirable segment of glass ribbon from the source 105 ofglass ribbon 103. For example, the monitoring device 193 may sense anundesired glass ribbon characteristic. In response, the controller 195can initiate a severing command, wherein the first storage roll 501 maythereafter be removed with high quality glass ribbon stored thereon.Next, a predetermined length of glass ribbon may be traversed throughthe system for disposal. For instance, as shown, a glass ribbon chopper507 may receive the predetermined length 103 b of glass ribbon havingundesired characteristics. Once the monitoring device 193 again senseshigh quality glass, the controller 195 can again initiate the severingcommand. After disposing of the predetermined length 103 b of glassribbon, subsequent high quality ribbon can then be stored on the secondstorage roll 503 (or again on the first storage roll 501 if desired).

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thespirit and scope of the claimed invention.

What is claimed is:
 1. A method of processing a glass ribbon comprisingthe steps of: (I) traversing the glass ribbon through a travel path at apredetermined velocity, the glass ribbon including a width extendingtransverse to the travel path between a first side edge and a secondside edge, wherein at least one of the first or second side edgeincludes a handling tab with a mounting portion including an apertureconfigured to expose the entire respective first or second side edgewithin a target area; (II) severing the glass ribbon at a first locationtransverse to the travel path; (III) severing the glass ribbon at asecond location transverse to the travel path such that a segment ofglass ribbon is severed from an upstream web including an upstreamsevered edge and a downstream web including a downstream severed edge;and (IV) removing the segment of the glass ribbon such that a gap iscreated between the upstream severed edge and the downstream severededge.
 2. The method of claim 1, wherein a sever path created during step(II) is substantially parallel to a sever path created during step(III).
 3. The method of claim 1, further comprising winding the severeddownstream web onto a first storage roll.
 4. The method of claim 3,wherein step (II) is initiated in response to the first storage rollreaching a predetermined storage capacity.
 5. The method of claim 3,wherein the downstream severed edge of the upstream web is introduced toa second storage roll to begin winding the upstream web on the secondstorage roll.
 6. A method of processing a glass ribbon comprising thesteps of: (I) traversing the glass ribbon through a first travel path ata predetermined velocity and winding the glass ribbon on a first storageroll, wherein the glass ribbon comprises a width extending transverse tothe first travel path between a first side edge and a second side edge,wherein at least one of the first side edge or the second side edgeincludes a handling tab with a mounting portion including an apertureconfigured to expose the entire respective first side edge or secondside edge within a target area; (II) severing the glass ribbon along adirection transverse to the first travel path through the at least oneof the first side edge or the second side edge within the target area tocreate an upstream web including a severed edge and a downstream webincluding a severed edge; and (III) directing the severed edge of theupstream web along a second travel path to create a gap between thesevered edge of the upstream web and the severed edge of the downstreamweb and winding the upstream web on a second storage roll.
 7. The methodof claim 6, wherein step (II) is initiated in response to the firststorage roll reaching a predetermined storage capacity.